19 research outputs found
Measurement of Spin Observables in the ~p ~d Breakup Reaction
No full textWe update our Letter-of-Intent 202 for Measurement of Spin Observables in the
~p ~d Breakup Reaction. An estimate of the overall beam time needed for completing
the measurements is specied and a timeline in view of the planned PAX experiments
is presented.
The proposal aims at a study of the three nucleon continuum in proton deuteron
breakup reactions, between 30 and 50 MeV proton beam energies, an energy range
where there have been few and limited measurements. The large coverage of the PAX
detection setup and the energy range chosen will provide essential new data intended
as a laboratory for chiral eective eld theory, the modern theory for nuclear forces
relevant at low and intermediate energies.
Vector and tensor analyzing powers and spin correlation coecients will be measured
and evaluated over large kinematical areas in the ve parameter phase space of
the nal state containing three nucleons. For the analysis the sampling method will
be used, a technique developed specically for the complex analysis of three particle
nal states, providing a direct comparison between experiment and theory
Extensive high precision studies of proton deuteron breakup reactions at COSY
No full textWe plan to measure the spin dependence of proton deuteron breakup at 30 and 49 MeV proton beam energy where previous measurements are few and limited. The physics objective is to test the predictive power of the chiral effective field theory in the three nucleon continuum by measuring analyzing powers and double spin observables with high precision over large areas of
phase space at relevant energies for the theoretical interpretation. The experiment will be done at a newly installed and commissioned low-β section and interaction point in the COSY ring utilizing the PAX Multipurpose Detection System that is presently in the design stage
Experimental search for evidence of the three-nucleon force and a new analysis method
No full textA research program with the aim of investigating the spin dependence of the three-nucleon continuum in pd collisions at intermediate energies was carried out at IUCF using the Polarized INternal Target EXperiments (PINTEX) facility. In the elastic scattering experiment at 135 and 200 MeV proton beam energies a total of 15 independent spin observables were obtained. The breakup experiment was done with a vector and tensor polarized beam of 270 MeV and an internal polarized hydrogen gas target. We developed a novel technique for the analysis of the breakup observables, the sampling method. The new approach takes into account acceptance and non-uniformities of detection efficiencies and is suitable for any kinematically complete experiment with three particles in the final state.</p
Phase measurement for driven spin oscillations in a storage ring
No full textThis paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV/c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles
Observation of a large longitudinal analyzing power in a nuclear reaction
No full textWe have measured the longitudinal analyzing power A(z) of the pp --> pp pi(0) reaction at 375 MeV bombarding energy. We find that for certain angle combinations of the outgoing particles the observed A(z) is as large as 0.3, demonstrating that sizeable lo</p
Observation of a large longitudinal analyzing power in a nuclear reaction
No full textWe have measured the longitudinal analyzing power A(z) of the pp --> pp pi(0) reaction at 375 MeV bombarding energy. We find that for certain angle combinations of the outgoing particles the observed A(z) is as large as 0.3, demonstrating that sizeable lo</p
"Measurement of the spin-dependence of p-pbar interaction at AD-ring”
No full textLetter of Intent to the CERN SPS Comitee.
An internal polarized hydrogen storage cell gas target is proposed for the AD--ring to determine for the first time the two total spin--dependent cross sections and at antiproton beam energies in the range from 50 to 200 MeV. The data will allow the definition of the optimum working parameters of a dedicated Antiproton Polarizer Ring (APR), which has recently been proposed by the PAX collaboration for the new Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany. The availability of an intense beam of polarized antiprotons will provide access to a wealth of single-- and double--spin observables, thereby opening a new window to QCD transverse spin physics. The physics program proposed by the PAX collaboration includes a first measurement of the transversity distribution of the valence quarks in the proton, a test of the predicted opposite sign of the Sivers--function, related to the quark distribution inside a transversely polarized nucleon, in Drell--Yan (DY) as compared to semi--inclusive Deep Inelastic Scattering, and a first measurement of the moduli and the relative phase of the time--like electric and magnetic form factors of the proton
Observation of large longitudinal analyzing power in a nuclear reaction
No full textWe have measured the longitudinal analyzing power A(z) of the pp --> pp pi(0) reaction at 375 MeV bombarding energy. We find that for certain angle combinations of the outgoing particles the observed A(z) is as large as 0.3, demonstrating that sizeable longitudinal analyzing powers in reactions with multi-particle final states are possible. This result has implications for pp parity violation experiments above the pion threshold. The observed A, is dominated by the interference between s and p wave pions in conjunction with nucleon-nucleon P waves in the final state. (C) 2000 Elsevier Science B.V. All rights reserved
How to Reach a Thousand-Second in-Plane Polarization Lifetime with 0.97−GeV/c Deuterons in a Storage Ring
No full textInternational audienceWe observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10−29 e cm
